A polysaccharide-based composition, characterized by comprising or essentially consisting of:at least a first component a) excluding galactane constituted by a substituted .beta.-1,4-linked glycan which is dissolvable in water of a certain temperature and which has a molecular weight (Mw) of .gtoreq.5.multidot.10.sup.4 Daltons, preferably.gtoreq.10.sup.5 Daltons, particularly .gtoreq.10.sup.6 Daltons, andat least a second component b), also excluding galactans, constituted by a substituted .beta.-1,4-linked glycan which is more difficult to dissolve than said first component at said temperature, or is agar or a carrageenan;the use of the composiiton above as a:a) means for reducing friction,b) means for facilitating removal of undesired contamination from surfaces, such as graffiti, scrawl, soot etc.,c) means for preserving moisture,d) protective surface coverage,e) packaging material,f) slow release matrix or coating for drugs;a body in solid phase having a surface intended for contact with a liquid and for relative movement between surface and liquid, said surface being coated with a solid film essentially consisting of such a composition; anda method for the removal of undesired contamination on a surface.